Obtaining function models using active vision strategies

This paper addresses the problem of determening which 3D shape is present, and more importantly, the dimensions of the shape within a scene. This is performed in an active vision system because it reduces the complexity of the problem through the use of gaze stabilisation, choice of foveation point and selective processing by adaptively processing regions of interest. In our case only a small number of equations and parameters are needed for each shape. For example, a container has width and height. These are incorporated into functional descriptions of the shapes.

Tracking in a space variant active vision system

Without the ability to foveate on and maintain foveation, active vision for applications such as surveillance, object recognition and object tracking are difficult to build. Although foveation in cartesian coordinates is being actively pursued by many, multi-resolution high accuracy foveation in log polar space has not been given much attention. This paper addresses the use of foveation to track a single object as well as multiple objects for a simulated space variant active vision system. Complex logarithmic mapping is chosen firstly because it provides high resolution and wide angle viewing. Secondly, the spatially variant structure of log polar space leads to an object increasing in size as it moves towards the fovea. This is important as we know which object is closer to the fovea at any instant in time.

An insect-based approach to robotic homing

Many animals, including insects, successfully engage in visual homing. We describe a system that allows a mobile robot to home. Specifically we propose a simple extension to our original homing scheme which significantly improves its performance by incorporating a richer view of the environment. The addition of landmark apparent-size cues assists homing by providing a more robust homing vector as well as providing a simple and effective method of reinforcing landmark avoidance. The homing algorithm allows a mobile robot to incrementally home by moving in such a way as to gradually reduce the discrepancy between the current view and the view obtained from the home position. Both simulation and mobile robot experiments are used to demonstrate the feasibility of this approach. By matching the bearings of features extracted from panoramic views and using a vector summation technique to compute a homing vector we are able to provide a simple, parsimonious and robust robotic homing algorithm.

Predatory vision : 3D imaging and the transformation of screen-space

Despite Wheatstone’s academic interests in the device, the stereoscope languished somewhat as an optical toy. Yet the advent of 3D screen-spaces for home and mass entertainment suggests today’s consumers and practitioners of screen culture hold the view that screen culture will be ‘improved’ through 3D imaging technologies. Like cinema and photography, stereoscopic 3D imaging has the potential to transform visual culture. But what is transformed, as optics and electronic imaging techniques deliver Alice in Wonderland in 3D? This paper links the advent of 3D cinema and TV to the notion that vision is itself a ‘technology of the visual’. As such, our innate binocular stereoacuity is ripe for exploitation by developers of 3D imaging technologies. I argue that contemporary 3D imaging marks an epistemological visual-perceptual shift: toward screenspaces becoming spaces for potential action. Such a shift entails seeing as doing rather than seeing as thinking. 3D imaging exploits binocular vision’s spatial acuity (stereopsis), but is effective only for objects within near distal space. The 3D effect tapers off dramatically for objects only some metres away, because the two retinal images lack significant lateral disparity (difference) to trigger stereopsis: the imagery flattens out and becomes ‘monoscopic’. Information available from conventional 2D media entails a peculiarly unspecified spatiality. Perceptually, the contents of a conventional cinematic screen are like those of a painting: they are situated neither near nor far, and constitute a shared and ambiguous visual space. Our own eyes are like those of a cat: frontally placed for predatory action. The visuality of 3D screen-spaces assumes a perceptuality of the near-by and close at hand, since this is the structure of the visible information to which stereopsis is adapted to respond. Noting the binocular acuity of predatory animals, as well as some etymological links, this paper examines the implications of perceptually ‘capturing’ the sensation of visually solid objects in one’s immediate space. Stereopsis is about decisive action within an immediate environment: but it also presupposes the single viewpoint of an active observer toward which the 3D imagery is targeted.

Click clack : examining the strategic and entrepreneurial brand vision of Under Armour

Using non-traditional brand strategy and innovative techniques, Under Armour quickly established a dominant presence in the sport performance apparel market as a newcomer in its product category. It established strong brand equity among consumers through its messaging and authentic relationship with target consumers. Utilising marketing and brand management theories, this study analysed the entrepreneurial strategies implemented by Under Armour in establishing the company's current positioning in the sport performance apparel marketplace. Using Aaker's (2005) strategic market management theory and Porter's (1980) competitive forces model as a framework, this study analysed the different marketing methods utilised to develop, maintain, and sustain the Under Armour brand.

Vision, ambiguity and perceptual possibility : why pictures matter in the critique of stereo-immersive VR

The acquisition of three-dimensional immersive space through advanced digitial imaging technology, suggests a profound shift from the relatively impoverished representational stratgies of two-dimensional pictorial imagery.  This entails an epistemological shift from pictorial representation, to the presentation of actual three-dimensional space through stereoscopic (3D) imagery.  Moreover, it suggests that visuality rather than 'virtuality' is the core issue in understanding the nature of the epistemological shift associated with stereo-immersive VR.

A shift in visual epistemology from 'flat' pictorial representation to three-dimensional stereo-immersion suggests a gainful move toward a visuality imbued with spatial possibilities.  In quantitative terms, these visual-spatial gains may seem self-evident.  However, certain aspects peculiar to pictorial representation are missing from stereo-immersive imaging.  That is lost in stereo-immersive imaging, and how it can be measured?

This thesis proposes that the inherent ambiguity of two-dimensional representations of three-dimensional spatial structure in pictures, invokes a perceptual response in which pictorial spaces elicit 'perceptual possibility'.  The robust three-dimentional spatiality of stereo-immersvie VR foreclosures such possibility.  Through examining stereo-immersive VR in terms of its visuality, the thesis develops a new appraoch to understanding VR that solves some of the issues associated with the problematic concept of 'virtuality'.  In addition, the thesis finds that by placing stereo-immersive VR and pictures within the shared paradigm of 'the visual', an important dimension of pictures that has been overlooked in past analyses re-emerges : the thesis proposes the concept of 'artifactuality' to account for the way pictures are fundamentally, and in the first instance, aesthetic objects for visual perception.  It is in their manner of appearing as pictures, that they are perceived as pictures of something.  It is from this fundamental basis that their many levels of meaning and signification - their manifold 'realisms' - can arise.

This thesis therefore addresses two intersecting problems within the paradigm of the visual: it proposes 1) that analyses of 'the virtual' be grounded in the 'artifactuality' of pictorial perception, and 2) that the spatiality of stereo-immersive VR be reinvigorated by purposefully 'under-contraining' its key percept - the robust, 'solid' stereoscopic structuring of visual space.  This approach opens up the discourse of stereo-immersive VR to new visual paradigms.  The thesis proposes that these be modelled not on the impossibility of 'the virtual', but on the possibilities of visual ambiguity drawn from the analysis of pictorial perception.

A randomised trial of robotic and open prostatectomy in men with localised prostate cancer

Background
Prostate cancer is the most common male cancer in the Western world however there is ongoing debate about the optimal treatment strategy for localised disease. While surgery remains the most commonly received treatment for localised disease in Australia more recently a robotic approach has emerged as an alternative to open and laparoscopic surgery. However, high level data is not yet available to support this as a superior approach or to guide treatment decision making between the alternatives. This paper presents the design of a randomised trial of Robotic and Open Prostatectomy for men newly diagnosed with localised prostate cancer that seeks to answer this question.

Methods
200 men per treatment arm (400 men in total) are being recruited after diagnosis and before treatment through a major public hospital outpatient clinic and randomised to 1) Robotic Prostatectomy or 2) Open Prostatectomy. All robotic prostatectomies are being performed by one surgeon and all open prostatectomies are being performed by one other surgeon. Outcomes are being measured pre-operatively and at 6 weeks and 3, 6, 12 and 24 months post-surgery. Oncological outcomes are being related to positive surgical margins, biochemical recurrence +/ the need for further treatment. Non-oncological outcome measures include: pain, physical and mental functioning, fatigue, summary (preference-based utility scores) and domain-specific QoL (urinary incontinence, bowel function and erectile function), cancer specific distress, psychological distress, decision-related distress and time to return to usual activities. Cost modelling of each approach, as well as full economic appraisal, is also being undertaken.

Discussion
The study will provide recommendations about the relative benefits of Robotic and Open Prostatectomy to support informed patient decision making about treatment for localised prostate cancer; and to assist in treatment services planning for this patient group. Trial Registration ACTRN12611000661976

The development of the Melbourne low vision ADL index : a measure of vision disability

PURPOSE. To develop a new test of activities of daily living (ADLs) appropriate for the low-vision population: the Melbourne Low-Vision ADL Index (MLVAI).

METHODS. The MLVAI was designed as a desk-based clinical assessment, comprising 18 observed items on complex ADLs in part (a) and 9 questions on broad self-care ADLs in part (b). Each item was rated on a five-level descriptive scale from 0 to 4, based on independence, speed, and accuracy of performance. It was designed to be administered under standardized conditions with regard to the instructions, illumination, and working distances. The validity and reliability of the new MLVAI was determined for 122 subjects who were representative of the general low-vision population, in a cross-sectional study.

RESULTS. Two items were found to be redundant and were eliminated from the test. Thus, the final test comprised 25 items, with 100 being the highest possible score. Cronbach’s α indicated an internal reliability of 0.96, and an intraclass correlation coefficient indicated an overall reliability of 0.95. The SE of measurement was 4.5. According to Spearman’s correlation coefficient, the test–retest reliability was 0.94 (P < 0.001), and the interpractitioner reliability for five different pairs of practitioners was 0.90 or higher (P < 0.001). With regard to validity, there was a moderately high correlation with vision impairment (r = −0.68, P < 0.001). Using Rasch analysis, content validity was also demonstrated by good separation indexes (4.70 and 9.88) and high reliability scores (0.96 and 0.99) for the person and items parameters, respectively. Separate calculation of indexes and reliability scores for parts (a) and (b) indicated high content validity and reliability of each part. However, the separation indexes and reliability scores were higher for part (a) than for part (b). The correlation coefficient for part (a) and part (b) was 0.68.

CONCLUSIONS. The MLVAI is a highly valid and reliable standardized test of ADL performance for the general low-vision population. It may be used to assess patients with low vision and has the potential to be used as a measure of low-vision rehabilitation outcomes.